Crew seating arrangement

Backup Crew

Flight

Launch from Cape Canaveral; landing 850 km
east of Florida in the Atlantic Ocean.

The Gemini spacecraft was a cone-shaped capsule
consisting of two components, a reentry module and an adaptor module. The
adaptor module made up the base of the spacecraft. It was a truncated cone
228.6 cm high, 304.8 cm in diameter at the base and 228.6 cm at the upper end
where it attached to the base of the reentry module. The re-entry module
consisted of a truncated cone which decreased in diameter from 228.6 cm at the
base to 98.2 cm, topped by a short cylinder of the same diameter and then
another truncated cone decreasing to a diameter of 74.6 cm at the flat top. The
reentry module was 345.0 cm high, giving a total height of 573.6 cm for the
Gemini spacecraft.The adaptor module was an
externally skinned, stringer framed structure, with magnesium stringers and an
aluminum alloy frame. The adaptor was composed of two parts, an equipment
section at the base and a retrorocket section at the top. The equipment section
held fuel and propulsion systems and was isolated from the retrorocket section
by a fiber-glass sandwich honeycomb blast shield. The retrorocket section held
the re-entry rockets for the capsule.The reentry module consisted mainly of
the pressurized cabin which held the two
Gemini astronauts. Separating the reentry module from
the retrorocket section of the adaptor at its base was a curved silicone
elastomer ablative heat shield. The module was composed predominantly of
titanium and nickle-alloy with beryllium shingles. At the narrow top of the
module was the cylindrical reentry control system section and above this the
rendezvous and recovery section which holds the reentry parachutes. The cabin
held two seats equipped with emergency ejection devices, instrument panels,
life support equipment, and equipment stowage compartments in a total
pressurized volume of about 2.25 cubic meters. Two large hatches with small
windows could be opened outward, one positioned above each seat.Attitude
control was effected by two translation-maneuver hand controllers, an attitude
controller, redundant horizon sensor sytems, and reentry control electronics,
with guidance provided via an inertial measuring unit and radar system. The
orbital attitude and maneuver system used a hypergolic propellant combination
of monomethylhydrazine and nitrogen tetroxide supplied to the engines by a
helium system pressurized at 2800 psi. Two 95 lb translation thrusters and
eight 23 lb attitude thrusters were mounted along the bottom rim of the
adaptor, and two 79 lb and 4 95 lb thrusters were mounted at the front of the
adaptor. Power was supplied by 3 silver-zinc batteries to a 22- to 30-volt DC
two-wire system. During reentry and post-landing power was supplied by four 45
amp-hr silver-zinc batteries.Voice communications were performed at 296.9
MHz with an output power of 3 W. A backup transmitter-receiver at 15.016 MHz
with an output power of 5 W was also available. Two antenna systems consisting
of quarter-wave monopoles were used. Telemetry was transmitted via three
systems, one for real time telemetry, one for recorder playback, and a spare.
Each system was frequency-modulated with a minimum power of 2 W. Spacecraft
tracking consisted of two C-band radar transponders and an acquisition-aid
beacon. One transponder is mounted in the adaptor with a peak power output of
600 W to a slot antenna on the bottom of the adaptor. The other is in the
reentry section, delivering 1000 W to three helical antennas mounted at 120
degree intervals just forward of the hatches. The acquisition-aid beacon was
mounted on the adaptor and had a power of 250 mW.At the time of reentry,
the spacecraft would be maneuvered to the appropriate orientation and equipment
adaptor section would be detached and jettisoned, exposing the retrorocket
module. The retrorockets consisted of four spherical-case polysulfide ammonium
perchlorate solid-propellant motors mounted near the center of the reentry
adaptor module, each with 11,070 N thrust. They would fire to initiate the
spacecraft reentry into the atmosphere, with attitude being maintained by a
reentry control system of 16 engines, each with 5.2 N thrust. The retrorocket
module would then be jettisonned, exposing the heat shield at the base of the
reentry module. Along with the ablative heat shield, thermal protection during
reentry was provided by thin Rene 41 radiative shingles at the base of the
module and beryllium shingles at the top. Beneath the shingles was a layer of
MIN-K insulation and thermoflex blankets. At an altitude of roughly 15,000
meters the astronauts would deploy a 2.4 meter drogue chute from the rendezvous
and recovery section. At 3230 meters altitude the crew releases the drogue
which extracts the 5.5 meter pilot parachute. The rendezvous and recovery
section is released 2.5 seconds later, deploying the 25.6 meter main ring-sail
parachute which is stored in the bottom of the section. The spacecraft is then
rotated from a nose-up to a 35 degree angle for water landing. At this point a
recovery beacon is activated, transmitting via an HF whip antenna mounted near
the front of the reentry module.

The Gemini Agena Target Vehicle (GATV) was designed to be launched into Earth orbit
prior to a
Gemini mission and used for rendezvous and docking
practice. The
GATV had a docking cone at the forward end into which
the nose of the
Gemini spacecraft could be inserted and held with
docking latches. The
GATV was a 6 meter long cylinder with a diameter of
4.9 meters. The primary and secondary propulsion systems were at the back end
of the target vehicle with the attitude control gas tanks and the main
propellant tanks. The docking cone was connected to the front end by shock
absorbing dampers. Acquisition running lights and target vehicle status display
indicators were situated on the front end. A 2.1 meter long retractable L-band
boom antenna extended from the side of the cylinder near the front. Tracking
and command of the
GATV were also aided by a rendezvous beacon, two
spiral L-band antennas, two tracking antennas (C-band and S-band), two VHF
telemetry antennas, and a UHF command antenna. Micrometeoroid packages and
other experiments could also be mounted on the
GATV. The
Gemini 10 Agena Target Vehicle (GATV-10) was successfully launched from Cape Kennedy
on July 18, 1966 at 20:39:46.131
UTC into a near-circular 300 km orbit.

Gemini 10 was launched on July 18, 1966 from Complex
19 at 22:20:26.648
UTC and inserted into a 159.9 x 268.9 km orbit. At
orbit insertion
Gemini 10 was about 1600 km behind the
Gemini Agena Target Vehicle 10 (GATV-10) which had been launched into a near circular
orbit about 100 minutes earlier.

The main objectives of this
mission were to dock with the Agena target vehicle
GATV-10 and to dock with the Agena Target Vehicle from
the Gemini 8 mission (GATV-8). After docking with
GATV-10 in low orbit, John
Young
and Michael
Collins should use it to climb to a high orbit to meet with
the dead, drifting Agena left over from the aborted
Gemini 8 flight - thus executing the
program's first double rendezvous. With no electricity on board the second
Agena the rendezvous was accomplished with eyes only - no radar. In addition
Michael
Collins was scheduled to perform a spacewalk. The mission
patch was drawn by Barbara Young (John
Young's wife at the time).

The docking with the
unmanned Agena target vehicleGATV-10 was successful (04:13:02
UTC), even it was need more fuel than planned. Michael
Collins learned that he was unable to use the sextant for
navigation as it did not seem to work as expected. At first he mistook airglow
as the real horizon when trying to make some fixes on stars. Then the image
didn't seem right. He tried another instrument that they had on board but this
was not practical to use as it had a very small field of view. They fortunately
had a backup in the form of the computers on the ground. To save fuel, planned
more docking and redocking maneuvers were not performed. During the docking the
GATV-10 primary propulsion system was used to raise
the dual spacecraft apogee to 764 km (a new record). The first burn of the
Agena engine they made was 80 seconds long and put them in a 294 by 764
kilometers orbit. This was the highest a person had ever been (until the next
mission when Gemini 11 went to over
1,000 kilometers (620 mi)). This burn was quite a ride for the crew. Because
the
Gemini and Agena docked nose to nose, the forces
experienced were "eyeballs out" as opposed to "eyeballs in" for a launch from
Earth.

Two
EVAs
were performed by Michael
Collins. The first was a standup-EVA
on July 19, 1966 (0h 38m) and Michael
Collins began photographing stellar UV radiation around the
Southern Milky Way.

After more 44 hours the
Gemini spacecraft separated from the
GATV-10 at 19:00:42
UTC. The
Gemini used its own thrusters to complete the second
rendezvous some three hours later with the
GATV-8 target vehicle. After a couple more correction
burns they were station keeping 3 meters away from the Agena.

Then the
second EVA on July 20, 1966 (0h 49m) was performed by
Michael
Collins. First he retrieved a micro meteorite experiment
mounted on the
Gemini 10 spacecraft, but he lost it, when it floated
out of the cabin during the
EVA.
He then walked from the
Gemini spacecraft to the Agena target vehicle to
retrieve the second micrometeorite package left in space all those months.
While doing this he lost grip in space walk from
Gemini to Agena, tumbled head over heels at end of
umbilical around
Gemini. Michael
Collins needed a second attempt using the hand-held gun to
turn back to the Agena, save the package and retrieved it. Returning into the
capsule was difficult, because Michael
Collins had gotten himself tangled in the umbilical. During
this EVA he lost his camera.

There were 10 other
experiments that the crew performed during the mission. Three were interested
in radiation. MSC-3 was the Tri-Axis Magnetometer which measured levels in the
South Atlantic Anomaly. There was also MSC-6, a beta spectrometer, measured
potential radiation doses for Apollo missions, and MSC-7, a bremsstrahlung
spectrometer which detected radiation flux as a function of energy when the
spacecraft passed through the South Atlantic Anomaly. More experiments were
about the Zodiacal light, about the ion and electron wake of the spacecraft and
a navigation experiment.

The reentry was performed without any problems.
Gemini 10 landed only 5.6 kilometers away from the
intended landing site. The recovery ship was the
USS
Guadalcanal.